This invention relates to organosilicone fine particles, as well as methods of their production and cosmetic materials, resin compositions and paint composition which contain such particles. Fine particles of various substances have been in use in many applications. Their shapes are mostly indefinite, and they are useful and have been playing their respectable roles as industrial materials. In recent years, however, as the characteristics required of them in various applications become highly advanced, there are beginning to appear many situations where fine particles with controlled shapes are desired. As examples, improvements in the optical characteristics in the field of display devices and optical diffusers, miniaturization in size in the field of electronic components, improvements in usability and feeling of cosmetic products and improvements in matte effect and factual sense in the field of paints may be considered. This invention relates to organosilicone fine particles in tetrahedral general shapes, having surfaces each comprising a concave part with an approximately circular opening.
There have been proposed many kinds of fine particles with controlled shapes such as those made of inorganic and organic materials. As for organic fine particles, Japanese Patent Publications Tokkai 09-103804 and 11-292907, for example, considered polystyrene fine particles, Japanese Patent Publication Tokkai 11-116649, for example, considered polyurethane fine particles, Japanese Patent Publication Tokkai 11-140181, for example, considered polyimide fine particles, and Japanese Patent Publication Tokkai 61-159427, for example, considered organosilicone fine particles. While almost all of these prior art fine particles are spherical or nearly spherical, however, there have in recent years been an increasing number of situations wherein problems were encountered by these spherical or nearly spherical fine particles not being able to respond to the highly advanced requirements which are imposed upon them recently for purposes of use as explained above. For organic fine particles with changed shapes, therefore, Japanese Patent Publication Tokkai 07-157672, for example, proposed hollow fine particles having protrusions and indentations, Japanese Patent Publication Tokkai 2000-191788, for example, proposed nearly spherical fine particles having a large number of small indentations on the surface, Japanese Patent Publication Tokkai 2003-171465, for example, proposed fine particles shaped like a rugby ball, and Japanese Patent Publication Tokkai 2003-128788, for example, proposed semispherical fine particles. Such prior art fine particles with changed changes, too, have problems of not being able to fully respond to the highly advanced requirements of recent years imposed on them for purposes of use.